1. Field of the Invention
The present invention relates to a viewfinder of a camera having a plurality of focus detection zones within the field of view.
2. Description of the Related Art
In recent single lens reflex (SLR) cameras having an automatic focusing function, a focusing plate which lies in a focal plane defined between a quick return mirror and a pentagonal daha prism is made of a plate having an entirely matted surface on which lines defining the focus detection zone are drawn. The photographer moves the camera to see the object in the focus detection zone (focusing area), so that the auto-focusing operation can be effected for the object. In general, the focus detection zone is located at the center portion of the field of view when viewed through a viewfinder. There is also known a multi-point type auto-focus camera having a plurality of focus detection zones.
However, in the known auto-focus SLR cameras the diffusion coefficient of the focusing plate is small to provide a bright field of view. Consequently, if the lens is focused on the object by the auto-focusing operation, it is difficult for the photographer to confirm whether or not an aimed object is in focus while viewing the object image within the finder. Moreover, in a multi-point type auto-focus SLR camera having a plurality of focus detection zones, it is difficult for the photographer to identify which objects in a plurality of the focus detection zones are in an in-focus condition. This is because, in a multi-point type auto-focus SLR camera in which the focusing function is achieved in the camera, it had not been considered important for the photographer to confirm the establishment of an in-focus state, and instead attempts have been made to provide a bright field of view.